Propeller with oil cooler



Jan 29, 1957 M. E. cUsHMAN PROPELLER WITH OIL COOLER Filed Aug. 25, 1955 a rtv l Imvcntor MAUR/CE f. CZ/HM/V States. Pate-nf Q 2,719,423 ROPELLER wrrn OIL COOLER Maurice E. Cushman, Verona, N. J., assignor to Curtiss- Wright Corporation, a corporation of Delaware Application August 25, 1953, Serial No. 376,307

4 Claims. (Cl. 170-160.23)

This invention relates to aeronautical propellers and is particularly concerned with propeller arrangements embodying spinners and Oil coolers.

As the development of large propellers for large power plants progresses, and also as improved propeller mountings on power plants are evolved, the bearings and pitch changing mechanisms of the propeller assembly absorb sufficient power so as to produce a significant temperature rise in operation. Cooling of these components may at times be accomplished most readily by cooling circulating oil used for lubricating them. In many instances, adequate cooling may be attained by routing the oil against surfaces of the propeller assembly which are kept fairly cool by their movement through the airstream in which the propeller operates. In some instances, however, it becomes necessary to provide heat transfer units in the form of coolers or radiators, whereby heat may be transferred from the lubricating oil to the airstream over a large radiating surface. When such radiation apparatus is utilized, the air which passes through the cooler and which is warmed thereby can effectively be used as a d warming medium `for portions of the propeller system such as the propeller spinner, which may at times require deicng.

The present invention discloses a propeller system incorporating an oil circulating system for lubrication and cooling of the propeller bearings and the pitch changing mechanism, and an oil cooler for cooling the lubricant. The cooler warms air used in lubricant cooling. A spinner arrangement is provided for the propeller, cooperating with the oil cooler in such a manner that heated air from the cooler is effectively used for spinner deicing. The invention is shown in a single embodiment and as applied to a particular propeller conguration. However, the principles of the invention are applicable to other types of propellers and to other arrangements of spinners and coolers on propellers.

Objects of the invention are: to provide a propeller bearing and pitch changing mechanism cooling system; to 'provide a good mechanical arrangement for an oil ooler used in conjunction with an aeronautical propeller; to provide a deicing spinner for a propeller; to combine a propeller oil cooler with a propeller spinner in such fashion that the cooler reduces the temperature of the propeller lubricant and increases the temperature o f the propeller spinner.

The details of the invention maybe better4 lunderstood by reading the annexed description in connection with the drawing, in ,which the single figure is a fragmentary longitudinal section through a propeller, spinner, and coolerarrangement. Y

The'propeller disclosed in the drawing is of a type similar to that disclosed in copending applications Serial No. 255,789 tiled November 10, 1951, now abandoned, and Serial No. 375,486 filed August 20, 1953, now abancloned., The propeller includes a hub having one or more blade sockets 11 in which propeller blades, not shown, are secured in known fashion for pitch change.

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The propeller hub has journalled thereon a non-rotating l pitch change mechanism encased in a housing 12, the latter being disposed on the rearward or inboard end of the propeller. The hub 10 with its associated parts is journalled on a non-rotating tubular shaft or journal member 13 for free rotation, the member 13 being secured to the nose of a power plant or reduction gear as shown in said prior applications. Bearings for supporting the propeller on the member 13 are indicated at 14 and 15. The propeller hub 10 is driven by a torque tube 16 within the shaft 13, the rearward end of the torque tube being secured to a driving member of the engine, and the forward end of the torque tube being secured to the propeller hub through a flexible coupling comprising diaphragms 17 and` 18 splined at their outer edges to each other as at 19, and splined respectively to the tube 16 at 20 and to the hub 10 at 21.

The housing of the pitch changing mechanism 12 forms a sump for lubricating oil and contains an oil pump 24 driven by rotation of the propeller, the pump picking up oil from the sump and delivering it through a passage 25 to the bearing 14. The latter includes a dam 14'.

the shaft 13 to the forward bearings 15. Thence, the oil enters an annular cavity 27 formed by an adapter 28 disposed between the forward end of propeller hub 10 and the tube 16. The adapter includes a running seal 29 engaging a retaining nut 30, the latter engaging the shaft 13 and securing the bearings 15 in place thereon. adapter 28 is provided with an oil transfer passage `31 leading-from the cavity 27 to a port 32 in the torque tube 16. Within the torque tube is a tting 34 having a port 35 registering with the port 32 and leading to a transfer plug 36 secured centrally in the fitting 34. Thence, `oil passes forwardly through a exible conduit 37 to a second transfer plug 36 engaging a titting 38 having a port 39 connecting with an inlet pipe 40 of an oil cooler 41. The latter is coaxial with the propeller shaft, is disposed ahead of, and rotates with the propeller.

The cooler 14 may comprise the usual array of encased radiator tubes through which cooling air passes and around which in the intertube passages, the oil passes. Oil leaves the cooler 41 through an exit pipe 42, through an exit duct 43 in the iitting 38 to the plug 36', through a exible conduit 44 secured to another plug 36' and thence to the fitting 34. The concentric conduits 37 and 44 define two oil passages, and these elements would normally be brazed to their end plugs 36 and 36 respectively as subassemblies. The unit 36, 37, 36 sleeves within the unit 36, 44, 36 and ports in the plugs visolate dow in one conduit from flow in the other. Exit oil passes through a port 45 in the itting 34 to a port 46 in the torque tube'lt and thence' into a port 47 in the adapter 28. The port 47 registers with the channel 48 in the propeller hub 1t) which leads to part of the pitch change gearing 50 within the propeller hub. At this point, oil

lubricates the bearings of gearing 510 and passes ther-ee from through an appropriate conduit 51 back to the sump in the pitch change mechanism housing 12. Gearing 50 includes the worm wheel and additional gearing Vwithin and carried by` the propeller hub,

By the apparatus and oil path above described, it will prises a closed circuit from the pump to the sump.` Leakage of oil can be prevented by appropriate sealing devices which are disposed at appropriate locations in the i Patented Jian. 29, 1,9574

The A oil passes through the bearing 14 and forwardlythroughV a conduit 26 formed by the space between the hub 10 and The #a a mechanism. The sealing problem is made comparatively simple since the oil circuit operates at low pressure.

As is conventional for many propellers, the propeller hub 1 0 is embraced by a. streamlined spinner 54, the,

spinner` having appropriate openings through which bladesof thef propeller project, and being supported on the propeller vhub by a bulkhead 5'5 at itsfor'wardend, andl vav bulkhead 56v at its-rearward end`. According to thepresentinvention, thenose of the spinner 54fis open and the material thereof is turned inwardly as at 57, theoil cooler 41 being fitted to this opening. front faceY ofthe oili cooler is thus exposed tothe air'- strearnvthrou'gh which the propeller travels and air passes intol and'through thetubesfof the cooler. Air issuing from the',v rear end ofthe cooler 41' is guided by anannula'rfbaiile arrangement comprising a cylindrical portion 5 8incllnd1n'g a closed, curved, rear; end 59. Thisportion'di'verts air so that it moves forwardly around the cooler,` The portionSS joins` a portiorndl at a joint 61,'V 'the portion 60 providing an inner wall for the spinner and deiining with the spinner proper an annular duct 62frunningalong the inner wall of theispinner. The bulkheads 55 vand 56 `are provided with openings 63 and 64g respectively, in the passage 62, so that air from thek cooler `may flow rearwardly within the spinner. The air passing through the cooler 41 is warmed by contact with the radiatingsurfaces of the cooler sothat flow of warm airjthrough the, passage 62 elevates the temperature Vof the spinnen This temperatureriseis sulicient to prevent ice` formation on the, spinner under those atmospherie conditions where ice is likely to form.

The spinner 5 4 which rotates. with the rpropeller comprisesl a forward streamlined prolongation of` a nonrotating annular cowling 6 6. The spinner 54 is sealed relative to the cowling 66 lby a seal ring 67 carried by the cowling, thus pre.venting. the premature escape ofv warm airf flowing. through the duct 62. They Cowling fembraces, in spaced relation, an inner cowling 69 which is also maintained in sealed relation to the spinner baille 60 by a sealing ring 70. The cowl'elements 66 and 169 are supported by a bulkhead 71, the bulkhead having openings 72 through which the warm air may pass. `At some appropriate point after the bulkhead 71, the cowling 66 has openings 74 for the exit of air from theV passage 62 into the freeairstream or into the air intake of the power plant which drives thepropeller. Should ittbejdesirable to exhaust the airfromv the passagef62'isomewhere along the spinner, eXit openings may be ,provided therein, the seals. 67 and 70 might be eliminated, and the bulkhead 56 could ldispense with openings 64.,

By the rarrangement shown and described, the oil cooler 41 serve sadual purpose. in reducing the temperature of the propeller circulating oil. and in elevating the temperature o f a quantity of air4 which canbe utilizedfor deicing purposes Von the spinner,

Though a` singleemb odiment.illustrating the invention is shownfit is to be understood that theinvention may be applied, in various forms and in various environments. Changes may be made in the arrangement shown withoutgdeparting from the spirit'of the invention. Referenceshouldbe had tothe appended claims for definition fof the limits of the invention.

What. ,iS' Claimed is;

1;"In'a tractor aircraft propellen,installatioinjagpr.

Pella?. having-a. Pitch Changing mechanism. indidina a circulatinglubricant pump and a sump feeding'said pump, means peratedby propeller rotation to drivel said pump, conduits in the propeller connected with bearings thereof fed lby said pump, an oil cooler mounted onthe outboard end of sa id kpropeller and rotatable therewith `connected to and receiving oil fromsaid conduits, additional conduits, connected to and receiving oil frornsaid cooler passing through said propeller and connected to parts of the mechanism thereof, means discharging oil from said'l additional conduits to said sump, a spinner embracing Said propeller to which said cooler is secured, the front end of said cooler passing through said spinner for exA posure to the airstream, and for passage of air through said cooler, and means withinsaid spinner to conduct air leaving the cooler, through said spinner and for discharge therefrom.

2. In. atractor. aircraft. propeller installati911;, a94 proa pellet Having` a Ptchchanginsmechanism-insluiting a circulating lubricant pump and a sump feeding said pump, means operated by. propeller rotationto drivesaidpurrp, conduits in the pr'OPeIIercQneted witllbear'ing's thereof fed by said pump, an oil cooler mounted on the outboard end of said propeller and rotatable therewith connected to and receiving oil from said conduits, additional conduits lcorlnected to andreceiving oil .fromsaidl cooler passing through Said Propeller andonnectedto partszqt the mechanism thereof, means,dischargingloiLfrom,said additionalconduits 'to Said, Sumpi a Spinner embracing saidpropeller to whichsaid cooler is.V secured, the frontfv en d of said cooler` passing through said spinner for. enf.. posure tothe airstream,` and for `J as`sag e,ofy air through saidv cooler,` and means within said spinner to conduct, air leaving the cooler, through said spinner and for dis-,b charge therefrom, said L latter means comprising ductngh ofl which thespinnerforms awall, whereby,- heatedain frornnhe oil cooler-is 4eifective forspinner deicing.

3. In an aircraftlpropeller system, a, propeller-includfA ing a` circulating..oilfsystem for.A the bearingsand.1t itehA changingrnechanisrnfthereof, a xedannular Cowling-aftv4 of the propeller, a spinner forandernbracingthe,hubo@ said propeller, a vrearward, end of l said l Spinner. blending with the` forWllfdpart. of said fixed: Cowling, an innerwall Vwitl'iin saidspinner defining therewith-an aire pasf, sage, an, inner wall within said lixed Cowling defining therewithan air passage-which is a continuation of said?l first air passage, sealing meansbetween the spinner-fand` Cowling, sealingumeans between thevspinnerinner wall, and the cowlinginner wall, said spinner at its frontfvend.. havinganairentrance opening communicating-with said airY passages, an o ilv cooler disposedv in the` spinner airv passa-ge,y andv Oil connections betweenl said cooler andi said circulatingoil system.

4. In an aircraftpropeller system, a propeller includ-` ing` a circulatingoil systemfor the bearings and pitch; changingfmechanism.; thereof, a fixed annular; Cowling; aft of` the propeller, a `spinner for and embracing the hub ofsaidpropeller, the rearward end of said/,spinnery blending witlithe forwardpart of` said fixed Cowling, an inner wall Within .said -spinner delininggtherewith an air.. passageVanlinner., wall within said fixed Cowling;defining therewith an air passage which is a continuation of said first air passage, seali ng me gns between the; spinner and Cowling` sealing means between thef, spinnerinnerwall and the' f cowling inner fwall, said spinner. at tsg-fronteend l having an air entrance` opening communicating withsaid. air paSsages, an.oilcooler-disposed in the spinner airpassage, and oilaconnections between said cooler and suidy circulating oil system, said oil connections beingflexible and separable from. said propellernpon yremoval ofthe cooler and spinner from said propeller.

Referensacited inthefile r,of .this-Patente UNITED STATES PATENTS- 2,423,1'752 Churchillet al.y g July l,v 1947 2,455,3l3 Osofsky` l N ov. l0, 19,48'.

2,627,927 f Mergen Feb. v10, 1953 2,668,596 Elliott Feb. 9, 1954 FOREIGN PATENTS 233,077" Switzerland Sept-16, V194,4x4 

